Bottom Line
The Decathlon Simond MT100 Down Puffer (men’s / women’s) (better known as the Forclaz MT100) has earned its cult following for good reason. It’s a warm, versatile, 800-fill down jacket that delivers incredible performance for the cost. Is it the warmest, best-fitting, or most premium option we tested? Not quite. But does it hold its own against jackets that cost twice as much? Absolutely.
During testing in Colorado’s chilly fall conditions, it offered solid warmth and comfort for everything from day hikes to casual wear. The design is simple yet practical, with the right features where they matter most. What really sets it apart is the sheer value: it’s rare to find a jacket this warm, light, and well-built at such an approachable price. For budget-conscious hikers and travelers looking for dependable warmth without breaking the bank, the MT100 is one of our favorite down jackets. See how it compares to the rest of our lineup in our guide to the best down jackets.
Note: Decathlon is in the process of rebranding the Forclaz MT100 to the Simond MT100. It’s the exact same jacket, just with a new name. The transition has been gradual, so some customers (like us) may receive jackets labeled Forclaz, while others get ones labeled Simond. Don’t worry, there are no design or material differences between the two.
How We Tested
We tested the Decathlon Simond MT100 Down Jacket across a wide range of conditions to see how it performs in real life. Over several weeks, our team wore it during chilly mornings and windy ridgelines in Colorado’s foothills and high country, as well as during damp, cold-weather hikes through the Appalachian Mountains of West Virginia and western Maryland.
The jacket faced everything from light snow to brisk fall temps, giving us a solid sense of its warmth, comfort, and durability in both alpine and humid mid-Atlantic environments.
Quick Specs
Decathlon Simond MT100 Hooded Down Puffer Jacket
Best Budget Down Jacket
CleverHiker Rating: 4.6/5.0
Price: $119
Weight: 11.3 oz. / 10.2 oz.(men’s / women’s)
Fill Power: 800
Fill Weight: n/a
Pros
- Price
- Lightweight
- Comfy
- Packable
Cons
- Runs small
- Could be warmer
- Odd cuff design
Comfort
In this review, you’ll hear us say we were surprised many times—and when it comes to comfort, the Decathlon Simond MT100 certainly exceeded our expectations. First and foremost, Decathlon recommends sizing up, noting on their website that their jackets tend to run small. We followed that advice and are glad we did. Our lead analyst typically wears a size large but opted for an XL. While the large probably would’ve worked, the XL is noticeably more comfortable, with a better fit, particularly through the torso.
Overall, the fit leans athletic. It’s somewhat form-fitting through the torso without feeling restrictive, with extra room in the chest and shoulders for freedom of movement during activities like climbing. The outer fabric feels durable and pleasant to the touch. While not as soft as some premium options we’ve tested, it doesn’t come across as cheap or fragile. The padded collar adds comfort without feeling bulky when fully zipped. The hood is elastic-brimmed, which helps it stay in place, though we’d love to see an adjustable cinch for windy or fast-moving days.
The cuffs use the same soft elastic as the hood and feel comfortable against bare skin. However, the design allows one down baffle to drape slightly over the elastic, adding warmth but occasionally extending over the tops of your palms. It’s a minor annoyance rather than a dealbreaker, but it is our biggest gripe about the jacket. Overall, the MT100 is quite comfortable and well-designed, especially considering its price.
Warmth
Budget-friendly down jackets often fall short in warmth, often due to awkward fit or lower-quality down. Thankfully, that’s not the case with the Decathlon Simond MT100. The MT100 provides plenty of warmth for its midweight design. Decathlon gives it a comfort rating of 41°F down to 23°F, a reasonable range depending on the user, layering system, and activity level. In our testing, it kept us comfortable on chilly hikes in Colorado’s foothills and during crisp mornings in the Appalachians.
The athletic fit helps trap heat and block out drafts, while the adjustable hem and insulated collar add extra protection in windy conditions. The 800-fill down insulation (a 90/10 duck down-to-feather blend) delivers solid loft and heat retention. While goose down is often seen as the gold standard, high-quality duck down like this performs nearly identically once fill power is equal.
Simply put, don’t expect the warmest jacket on the market, but the MT100 provides more warmth than you’d expect for its weight and price. It easily keeps up with jackets that cost twice as much, making it a killer pick for shoulder-season adventures and even light winter use.
Weight & Packability
At 11.3 ounces for an XL, we have no complaints about the Simond MT100’s weight. It lands on the lighter side of the midrange in our lineup.
The MT100 packs easily into its own pocket without a wrestling match — something we can’t say for all down jackets. Once stowed, a handy webbing loop lets you clip it to your pack for quick access. While duck down is said to be less compressible than goose down, we honestly couldn’t tell the difference here. The MT100 packs down to roughly the size of a Nalgene bottle, making it impressively portable and easy to toss in your bag for any adventure.
Weather Resistance
It’s no secret that down jackets aren’t built for rain. Once down insulation gets wet, it loses its loft and basically stops insulating, something we mention in every down jacket review. It’s just the nature of the beast. Some models perform a bit better thanks to hydrophobic down and a durable water repellent (DWR) finish on the shell, but those features only buy you time before moisture wins out.
The Simond MT100 doesn’t use hydrophobic down, but it does feature a surprisingly effective DWR coating. It held up well for us in light rain, snow, and damp conditions throughout Colorado’s foothills and high country. Would we trust it in truly wet conditions like those found in the Pacific Northwest? Not without a rain shell lay over the top. We wouldn’t push it in steady rain, but for mist, drizzle, or light flurries, it sheds water just fine.
The elastic cuffs, insulated collar, and cinchable hem all do their part to keep wind and cold air out. We do wish the hood had an adjustable drawcord to lock in warmth during gusty weather, but overall, the MT100 does a fair job protecting against the elements for its weight and price.
Breathability
Like most ultralight down jackets, the Simond MT100 isn’t built with breathability as a top priority. It’s made to trap heat, not let it escape. Still, it handles active use reasonably well for its design. During testing, the jacket stayed comfortable during moderate movement in cool conditions, but started to trap heat quickly when we picked up the pace and or when climbing.
There are no features to dump heat. There are no pit zips, no mesh panels, and no two-way zipper for venting, so managing temperature largely comes down to layering strategy. Leaving the hem cinch loose helps a bit with airflow, but once we start sweating, we unzip or shed the puffer entirely.
While it’s not meant for high-output use, the MT100 still allows for enough airflow for casual hiking and shoulder-season adventures. For anything more aerobic, we pair it with a lightweight, more breathable midlayer underneath.
Should You Buy the Decathlon Simond MT100 Hooded Down Puffer?
If you’re a hiker, backpacker, or someone who wants an affordable down layer to toss on for everything from shoulder-season hikes to cold mornings in the garage, the Simond MT100 is a safe bet. It’s not the warmest, lightest, or most technical jacket out there, but that’s not really the point. It delivers dependable warmth, good comfort, and solid weather resistance at a fraction of the cost of most comparable down jackets.
The fit is athletic without feeling restrictive, and the 800-fill down keeps things cozy without adding bulk. Sure, there are more premium jackets out there with higher-end materials and features, but for everyday outdoor use, travel, or casual winter wear, this one punches way above its price tag. The bottom line: if you want reliable warmth on a budget, the MT100 is tough to beat.
What Other Down Jackets Should You Consider?
If you like the Decathlon Simond MT100 but want to explore other top-performing options, check out our guide to the best down jackets for more recommendations.
REI 650 Down Jacket Review: If you like the MT100’s unbeatable warmth-to-value balance, the REI 650 Down Jacket plays in the same league. It’s a solid choice for budget-minded hikers who prefer ordering through REI and want to add a little to their member dividend. It’s a bit bulkier, has a more casual cut, and skips the hood, but still delivers dependable warmth and durability for everyday use and light adventures.
REI Magma 850 Down Hoodie Review: The Magma 850 takes performance up a notch with premium goose down, an ultralight design, and great packability. It’s a great choice for backpackers or alpine trekkers who need more warmth than the Simond offers. The Magma does cost quite a bit more, but the fit is a bit better and the materials are a bit more refined.
Rab Microlight Alpine Down Jacket Review: For those who want a down jacket that’s as at home on a mountain summit as it is around town, the Rab Microlight Alpine is tough to beat. It’s built with top-notch materials, wind-resistant Pertex Quantum fabric, and responsibly sourced hydrophobic down for better weather resistance than the MT100. It’s heavier and pricier, but it’s also a proven performer in harsh conditions.
